Sensing and/or transmission coverage adaptation using interference information

ABSTRACT

Methods and apparatus, including computer program products, are provided for sensing and/or transmission coverage adaptation using interference information. In one aspect there is provided a method. The method may include determining, at a node, a degree of interference at the node; receiving, at the node, at least one message from at least one neighboring node, the at least one message including another degree of interference observed at the at least one neighboring node; and adjusting, by the node based on the degree of interference at the node and the at least another degree of interference, at least one of a receiver sensitivity of the node, a clear channel assessment detection range of the node, or a transmit power of the node. Related apparatus, systems, methods, and articles are also described.

FIELD

The subject matter described herein relates to wireless communications.

BACKGROUND

Wireless devices may access a network based on a carrier sense multipleaccess (CSMA) protocol in order to avoid simultaneous transmission amongneighboring nodes and interference. To that end, a wireless device maylisten on a given channel. If the channel is clear, the wireless devicemay transmit on that channel. But if the channel is being used byanother wireless device, the wireless device backs off and waits acertain amount of time (which in some cases can be a random amount oftime) before listening and trying to transmit on the channel again.

SUMMARY

Methods and apparatus, including computer program products, are providedfor sensing and/or transmission coverage adaptation using interferenceinformation.

In some example embodiments, there is a method. The method may includedetermining, at a node, a degree of interference at the node; receiving,at the node, at least one message from at least one neighboring node,the at least one message including another degree of interferenceobserved at the at least one neighboring node; and adjusting, by thenode based on the degree of interference at the node and the at leastanother degree of interference, at least one of a receiver sensitivityof the node, a clear channel assessment detection range of the node, ora transmit power of the node.

In some variations, one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The adjusting may determine a difference betweenthe degree of interference at the node and the at least another degreeof interference of the at least one neighboring node, and the adjusting,based on the difference, at least one of the receiver sensitivity of thenode or the clear channel assessment detection range of the node. Thedetermining may listen to at least one beacon transmitted by the atleast one neighboring node. An aggregate may be determined for the atleast another degree of interference, wherein the adjusting is based onthe aggregate of at least one of the receiver sensitivity of the node,the clear channel assessment detection range of the node, or thetransmit power of the node, wherein the at least another degree ofinterference comprises degree of interference values for at least twoneighboring nodes. The aggregate may include at least one of a median, amode, a second order statistic, or a weighted average. The method mayfurther include adjusting, for a first time period, the clear channelassessment detection range of the node to a first range; and adjusting,for a second time period, the clear channel assessment detection rangeof the node to a second range. The adjusting may include increasing theclear channel assessment detection range of the node to increase thedegree of interference of the node. The adjusting may include decreasingthe clear channel assessment detection range of the node to decrease thedegree of interference of the node. The node may include an accesspoint.

The above-noted aspects and features may be implemented in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. The details of one or more variations of the subjectmatter described herein are set forth in the accompanying drawings andthe description below. Features and advantages of the subject matterdescribed herein will be apparent from the description and drawings, andfrom the claims.

DESCRIPTION OF DRAWINGS

In the drawings,

FIG. 1 illustrates a node, such as a Wi-Fi station (STA), and itscorresponding clear channel assessment range, in accordance with someexample embodiments;

FIG. 2 illustrates a Wi-Fi station, such as an access point (AP), andits corresponding partial interference graph depicting a contentiondomain or interference degree of 2, in accordance with some exampleembodiments;

FIG. 3 illustrates another example of a Wi-Fi station, such as an accesspoint (AP), and its corresponding partial interference graph depicting acontention domain or interference degree of 5, in accordance with someexample embodiments;

FIG. 4A illustrates the imbalance in the size of contention domains, inaccordance with some example embodiments;

FIG. 4B illustrates an example of a process for adjusting clear channelassessment range, receiver sensitivity, and/or transmit power, inaccordance with some example embodiments;

FIG. 5 illustrates the effect of clear channel assessment range (orreceiver sensitivity) changes, in accordance with some exampleembodiments;

FIG. 6 illustrates an example of periodic range adjustment, inaccordance with some example embodiments;

FIG. 7 illustrates an example frame structure including informationelements carried by a beacon, in accordance with some exampleembodiments;

FIG. 8 depicts an example of an apparatus, in accordance with someexemplary embodiments.

Like labels are used to refer to same or similar items in the drawings.

DETAILED DESCRIPTION

Wi-Fi devices, such as a station (STA), may access a network based on acarrier sense multiple access (CSMA) protocol in order to avoidsimultaneous transmission among neighboring nodes and interference. Tothat end, a Wi-Fi device may operate its receiver to have a certainclear channel assessment (CCA) detection range that covers the basicservice set (BSS) of the neighboring Wi-Fi devices being served by theWi-Fi device. As such, the Wi-Fi device's receiver may make a clearchannel assessment by listening for neighboring devices beforetransmitting on a given channel.

Wi-Fi networks are evolving into so-called “High Efficiency WirelessLocal Area Networks” (HEW), in which W-Fi operation may operate atgreater speeds (for example, 10 Gigabits per second or more) and inhigher density environments. The Wi-Fi carrier sense multiple access(CSMA) protocol relies on listening to transmissions as a way to avoidsimultaneous transmissions and interference. Before transmitting data, anode, such as a station (STA) or an access point (AP), may listen foractivity on a channel and may begin sending data when the nodedetermines, based on the listening, that other nodes are idle (forexample, not actively transmitting on the channel). The node's receivermay be sufficiently sensitive to detect most transmissions in the basicservice set (BSS).

FIG. 1 depicts a node, such as STA 112, communicating via Wi-Fi toanother node, such as an access point (AP) 110. The clear channelassessment (CCA) detection range 116 covers the basic service set (BSS)of the entire area 114 being served by access point 110. Tuning the CCAdetection range 116 may affect the performance of Wi-Fi as it is likelythat nodes from adjacent networks (for example, overlapping basicservice set, OBSS, nodes) may trigger the CCA avoidance mechanism asdepicted at FIG. 2.

FIG. 2 depicts a node 205 having a relatively small CCA range 250including two other nodes 210 and 220. Tuning the CCA range 250 of node205 may thus change the size of the CCA area 250 (or range) to includemore (or fewer) other nodes in the CCA area.

FIG. 2 also depicts a partial interference graph including the twopotential interferers, such as nodes 210 and 220. From the point of viewof node 205, the contention domain of the clear channel assessment maybe a set of neighboring nodes to node 205, and these neighboring nodesmay have sufficient transmit power to trigger a CCA channel accessdeferral at node 205. For example, nodes 210 and 220 may have a receivedsignal power, as measured at node 205, that is greater than a receiversensitivity threshold of about −82 dBm (milliwatts), although otherpower threshold values may be used as well. In the example of FIG. 2,the contention domain of neighboring nodes 210 and 220 may represent aninterference degree of 2 as shown by the partial interference graph. Inthe current 802.11 standard, the CCA threshold is fixed for each node.

However in dense networks, such as HEW deployment environments, thecontention domain for each node may be varied based on the topology ofthe network deployment. For example, Wi-Fi networks deployed in thecenter of an apartment or office building may experience more contentionthan Wi-Fi networks deployed at the edge or periphery of the building.As such, these networks having higher interference degrees or contentionmay receive a proportionally smaller amount of channel access time, whencompared to less densely deployed networks. As such, the networks havinghigher interference degrees or contention and the correspondingproportionally smaller amount of channel access time may result in adegree of unfairness for those networks. This is illustrated in FIGS. 2and 3. FIG. 3 also depicts node 205 with a different CCA range and thusa different degree of interference, when compared to FIG. 2. In FIG. 2,the node 205 contends for access with only 2 other nodes, while in FIG.3 the contention domain is larger (for example, includes five nodes 210,220, 305, 310, and 320 within the CCA range 350). As such, there may bea fundamental contention domain unfairness for node 205 in FIG. 3, whencompared to node 205 in FIG. 2.

In some example embodiments, the subject matter disclosed herein mayprovide mitigation of contention domain unfairness in a distributed way,and the mitigation may be implemented with a minimal amount of signalingand/or in a distributed manner with little (or no) centralized control.

In some example embodiments, there may be provided partial interferencegraphs as a measure of contention or degree of interference. In someexample embodiments, a process may be provided to infer the partialinterference graph based on detected (for example, received, listenedto, overheard, and/or the like) frames carried via Wi-Fi beacons.

In some example embodiments, a process may affect channel accessfairness by modifying CCA range, receiver sensitivity thresholds, and/ortransmitter power. The modification may be based on determined degree ofinterference (or contention degree) and/or partial interference graphsfrom adjacent/neighboring nodes.

In some example embodiments, a process for periodic expansion and/orcontraction of a receiver's sensitivity and CCA range/threshold may beimplemented to minimize channel access deferrals.

In some example embodiments, there may be provided improved channelaccess probability for nodes that are in high contention domains at thecost of reduced channel access at nodes with smaller contention domains.In short, a relatively fairer scheme for accessing the channel inhigh-density scenarios may be provided.

Although some of the examples herein refer to Wi-Fi and HEW, the subjectmatter disclosed herein may be used in other wireless systems as well.Moreover, although some of the examples refer to Wi-Fi nodes, such asSTAs and APs, the devices may be implemented as for example multi-moderadios, such as a cellular user equipment including a Wi-Fi radio aswell as other radio technologies.

The following examples illustrate various types of Wi-Fi/HEW networktopologies. In the following example networks, each of the networks mayhave a fixed contention domain threshold (CCA threshold) and/or may havea local partial interference graph depicted. Some networks may contendwith only a few other nodes/networks (see, for example, case 2 at FIG.4A) while others may contend with more nodes/networks (see, for example,cases 1 and 3 at FIG. 4A). As a result, the node/networks contendingwith fewer other nodes/networks may access the channel for acorrespondingly larger period of time, which represents unfairness whencompared to networks having more contention.

In some example embodiments, an AP's rseceiver sensitivity may remain ina range sufficient to decode signals from all STAs associated to the AP.The AP's receiver sensitivity value may be set dynamically based on forexample a minimum received signal strength from among the list of STAsassociated with the AP. Moreover, there may be a minimum (or floor)receiver sensitivity threshold. This receiver sensitivity thresholdvalue may be specified. Furthermore, the AP's transmit power may beadjusted, so that transmit power is sufficient to enable decoding of adownlink frame at the associated STA(s).

In some example embodiments, an access point may record the identity ofbeacons detected from other access points (and/or STAs in overlappingbasic service sets). Next, the AP may count the number of the detectedaccess points to derive its own interference degree (or contentiondomain). The access point may then advertise its own interference degreeusing its beacon so that other access points are aware of theinterference degree. The access point may then determine a differencebetween its own interference degree and the interference degree of oneor more surrounding networks (which also advertise in their beaconstheir interference degree). Based on the determined difference, the APmay then adapt (for example, maintain, increase, and/or decrease) itsreceiver sensitivity and/or CCA range. For example, if neighboringinterference degrees are larger on average, the AP may increase its CCArange (or decrease its receiver sensitivity threshold so that it detectsweaker signals) to capture more networks. However, if neighboringinterference degrees are smaller on average, the AP may reduce its CCArange (or increase its receiver sensitivity threshold so that it is lessable to detect weaker signals). Alternatively or additionally, the APmay fix the receiver sensitivity and adjust AP transmit power based onthe number of overlapping basis service set.

FIG. 4A depicts an access point informing neighboring access points ofthe interference degree or contention domain, in accordance with someexample embodiments. For example, access point 405 may send aninterference degree of 5; access point 410 may send to nodes 405 and 420an interference degree of 2, while access point 420 may send to nodes405, 410, and 430-450 and interference degree of 5. Each access point atFIG. 4A may record the identity of detected beacons from otherneighboring access points. For example, AP 410 may record the identityof detected beacons for access points 405 and 420. Next, access points410 may count the number of the detected access points to derive its owninterference degree. In this example, the interference degree for accesspoint 410 is 2. Access point 410 may then advertise the interferencedegree via for example its beacon, so that other, neighboring accesspoints are aware of the interference degree. Access point 410 may alsoreceive via the beacons of access point 405 and 420 the interferencedegrees of access points 405 and 420. In this example, access points 405and 420 each have an interference degree of 5. AP 410 may determine thedifference between its interference degree and those of surroundingnetwork. In this example, access point 410 may determine a difference of3 (i.e., an average neighboring node interference degree of 5 minus 2).Although an average of the interference degrees is described in theprevious example, the interference degrees from one or more neighbornodes may be combined in other ways as well (for example, a median, amode, 2nd order statistics such as standard deviation, a weightedaverage based on how close the neighboring node is, and the like).

Based on the determined difference, access point 410 may adapt (forexample, maintain, increase, and/or decrease) one or more thresholds,such as a receiver sensitivity threshold affecting CCA range. In thisexample, neighboring nodes 405 and 420 have interference degrees thatare on average larger than the interference degree of access point 410.When this is the case, access point 410 may increase its CCA range (forexample, by making its receiver more sensitivity by decreasing itsreceiver sensitivity threshold so it captures weaker and thuspotentially more access points). In addition and/or alternatively, theinterference degree information can be used to reduce transmit power atthe access point 410 in order to limit contention with neighboring nodesin the basic service set. Moreover, the access point may, as noted,adhere to floor and/or cap (e.g., a minimum and/or a maximum) values forCCA range, receiver sensitivity, and/or transmit power.

FIG. 4B depicts an example process 400 for adjusting, based ininterference degree, CCA range, receiver sensitivity, and/or transmitpower, in accordance with some example embodiments. The description ofFIG. 4A also refers to FIG. 4A.

At 472, a node, such as access point 410, may advertise it interferencedegree, in accordance with some example embodiments. For example, accesspoint 410 may detect neighboring nodes based on beaconsreceived/detected by the access point 410. For example, neighboringaccess points, such as access points 405 and 420 may each transmit abeacon, which may be detected by access point 410. The access point 410may then determine the contention domain for the CCA area given itscurrent receiver sensitivity. For example, access point 410 maydetermine its contention domain (or interference degree) as 2. Accesspoint 410 may then advertise the determined interference degree of 2 toits neighboring nodes via for example a beacon, which may be configuredas described with respect to FIG. 7 below. Each of the other nodes, suchas nodes 405 and 420, may also determine an interference degree and thenadvertise via a beacon the determined interference degree to itsneighboring nodes.

At 474, a node, such as access point 410, may receive the interferencedegree from one or more neighboring nodes, in accordance with someexample embodiments. For example, access point 410 may receive thebeacons from neighboring access points 405 and 420. The access point 410may determine an aggregate value, in some example embodiments,representative of the interference degree of the neighboring nodes 405and 420. For example, the aggregate value may be an average of theinterference degrees of each of the neighbors, although the aggregatemay be determined in other ways (such as determining a medianinterference degree among the neighbors, selecting a maximuminterference degree from among the neighbors, determining a median,determining a mode, determining 2nd order statistics, a weighted averagebased on how close the neighboring node is, and/or the like).

At 476, a node, such as access point 410, may determine a differencebetween its interference degree and the aggregate interference degreesof the neighboring nodes, in accordance with some example embodiments.For example, access point 410 may determine a difference of 3, whichrepresents the difference between access points's 410 interferencedegree (2) and the aggregate interference degree (5) of neighboringnodes 405 and 420.

At 478, a node, such as access point 410, may adjust CCA range, receiversensitivity, and/or transmit power in accordance with some exampleembodiments. For example, access point 410 may adapt, based on thedifference between its interference degree and that of its neighbors,one or more thresholds, such as a receiver sensitivity thresholdaffecting CCA range. In the example of FIG. 4A, neighboring nodes 405and 420 have interference degrees that are on average larger than theinterference degree of access point 410, so access point 410 mayincrease its CCA range (for example, by decreasing a sensitivitythreshold at the receiver) to capture more access points and thus makingaccess point's 410 degree of interference more comparable to itsneighbors. This may provide an overall improvement in channel accessprobability for the neighboring nodes (which are in a higher contentiondomain) at the cost of reduced channel access for node 410 (which priorto the adjustment at 478 had a smaller contention domain).

FIG. 5 depicts the second case depicted at FIG. 4 but in the example ofFIG. 5, access point 410 may expand, based on the interference degree,its CCA range from 510 to 520 so that its interference degree is morebalanced with respect to its neighbors.

Although the previous example was described with respect to access point410, the process 400 may be distributed among one or more access points,so that one or more other access points may implement process 400 andadjust CCA range, receiver sensitivity, and/or transmit power inaccordance with some example embodiments.

FIG. 6 depicts access point 605 during a first time period having afirst CCA range and during a second time period having a second CCArange, in accordance with some example embodiments. In some instances,it may be difficult to determine a contention reduction without changesto the receiver sensitivity that takes the sensitivity outside of theminimum threshold or maximum threshold noted above. As noted, theminimum (or floor) receiver sensitivity threshold may be set at anaccess point, so the access point cannot reduce its receiver sensitivitythreshold below this minimum signal strength (so the access point canserve the weakest/farthest STA associated to it). When the floor/minimumis used, the access point may be configured to serve edge nodes fromtime to time (for example, periodically) in the interest of overallfairness and performance. In the example of FIG. 6, access point 605may, during the first period, operate using a receiver sensitivity thatis low enough that access point 605 will not detect (or will ignore) oneor more edge STAs 618-620. During the second period, access point 605may adjust its receiver sensitivity to serve all nodes 630, 632, 618,and 620.

In the example of FIG. 6, the two time periods with different receiversensitivities may allow better frequency reuse for a larger portion oftime while maintaining service to edge nodes in the basic service set(BSS). Indeed, the periodic expansion/contraction can be employed toshrink the number of overheard basic service set to zero in some cases.The information regarding start/end of each such period may be providedthrough the access point beacon. If a STA is not covered during thefirst period, the STA may wait until the second period to transmit anypackets to access point 605.

To inform neighboring access points of the interference degree and/orinform nodes of the periodicity of range expansion/contraction, one ormore information elements may are added to the Wi-Fi beacon, althoughthe information may be signaled in other ways as well.

FIG. 7 depicts an example of a structure for the information elementscarried by a beacon including the extensions for interference degree702, first time period 704, and/or the second time period 706. Theinterference degree 702 may be represented using for example a fixednumber of bits capped at a certain level (for example, maximuminterference degree can be 15 with 4 bits) and the periodicity 704-708can be expressed in multiples of a time unit (for example, milliseconds)with a fixed number of bits. The additional fields 702-706 in the beaconmay be sufficient to inform neighboring APs of localinterference/contention conditions as well as inform the nodes ofrelevant sensitivity periods.

FIG. 8 illustrates a block diagram of an apparatus 10, in accordancewith some example embodiments. The apparatus 10 (or portions thereof)may be configured to provide a STA, such as an access point, node, userequipment, and/or the like.

The apparatus 10 may include at least one antenna 12 in communicationwith a transmitter 14 and a receiver 16. Alternatively transmit andreceive antennas may be separate. The apparatus 10 may also include aprocessor 20 configured to provide signals to and receive signals fromthe transmitter and receiver, respectively, and to control thefunctioning of the apparatus. Processor 20 may be configured to controlthe functioning of the transmitter and receiver by effecting controlsignaling via electrical leads to the transmitter and receiver.Likewise, processor 20 may be configured to control other elements ofapparatus 10 by effecting control signaling via electrical leadsconnecting processor 20 to the other elements, such as a display or amemory. The processor 20 may, for example, be embodied in a variety ofways including circuitry, at least one processing core, one or moremicroprocessors with accompanying digital signal processor(s), one ormore processor(s) without an accompanying digital signal processor, oneor more coprocessors, one or more multi-core processors, one or morecontrollers, processing circuitry, one or more computers, various otherprocessing elements including integrated circuits (for example, anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), and/or the like), or some combination thereof.Accordingly, although illustrated in FIG. 8 as a single processor, insome example embodiments the processor 20 may comprise a plurality ofprocessors or processing cores.

Signals sent and received by the processor 20 may include signalinginformation in accordance with an air interface standard of anapplicable cellular system, and/or any number of different wireline orwireless networking techniques, comprising but not limited to Wi-Fi,wireless local access network (WLAN) techniques, such as Institute ofElectrical and Electronics Engineers (IEEE) 802.11, 802.16, and/or thelike. In addition, these signals may include speech data, user generateddata, user requested data, and/or the like.

The apparatus 10 may be capable of operating with one or more airinterface standards, communication protocols, modulation types, accesstypes, and/or the like. For example, the apparatus 10 and/or a cellularmodem therein may be capable of operating in accordance with variousfirst generation (1G) communication protocols, second generation (2G or2.5G) communication protocols, third-generation (3G) communicationprotocols, fourth-generation (4G) communication protocols, InternetProtocol Multimedia Subsystem (IMS) communication protocols (forexample, session initiation protocol (SIP) and/or the like. For example,the apparatus 10 may be capable of operating in accordance with 2Gwireless communication protocols IS-136, Time Division Multiple AccessTDMA, Global System for Mobile communications, GSM, IS-95, Code DivisionMultiple Access, CDMA, and/or the like. In addition, for example, theapparatus 10 may be capable of operating in accordance with 2.5Gwireless communication protocols General Packet Radio Service (GPRS),Enhanced Data GSM Environment (EDGE), and/or the like. Further, forexample, the apparatus 10 may be capable of operating in accordance with3G wireless communication protocols, such as Universal MobileTelecommunications System (UMTS), Code Division Multiple Access 2000(CDMA2000), Wideband Code Division Multiple Access (WCDMA), TimeDivision-Synchronous Code Division Multiple Access (TD-SCDMA), and/orthe like. The apparatus 10 may be additionally capable of operating inaccordance with 3.9G wireless communication protocols, such as Long TermEvolution (LTE), Evolved Universal Terrestrial Radio Access Network(E-UTRAN), and/or the like. Additionally, for example, the apparatus 10may be capable of operating in accordance with 4G wireless communicationprotocols, such as LTE Advanced and/or the like as well as similarwireless communication protocols that may be subsequently developed.

It is understood that the processor 20 may include circuitry forimplementing audio/video and logic functions of apparatus 10. Forexample, the processor 20 may comprise a digital signal processordevice, a microprocessor device, an analog-to-digital converter, adigital-to-analog converter, and/or the like. Control and signalprocessing functions of the apparatus 10 may be allocated between thesedevices according to their respective capabilities. The processor 20 mayadditionally comprise an internal voice coder (VC) 20 a, an internaldata modem (DM) 20 b, and/or the like. Further, the processor 20 mayinclude functionality to operate one or more software programs, whichmay be stored in memory. In general, processor 20 and stored softwareinstructions may be configured to cause apparatus 10 to perform actions.For example, processor 20 may be capable of operating a connectivityprogram, such as a web browser. The connectivity program may allow theapparatus 10 to transmit and receive web content, such as location-basedcontent, according to a protocol, such as wireless application protocol,WAP, hypertext transfer protocol, HTTP, and/or the like.

Apparatus 10 may also comprise a user interface including, for example,an earphone or speaker 24, a ringer 22, a microphone 26, a display 28, auser input interface, and/or the like, which may be operationallycoupled to the processor 20. The display 28 may, as noted above, includea touch sensitive display, where a user may touch and/or gesture to makeselections, enter values, and/or the like. The processor 20 may alsoinclude user interface circuitry configured to control at least somefunctions of one or more elements of the user interface, such as thespeaker 24, the ringer 22, the microphone 26, the display 28, and/or thelike. The processor 20 and/or user interface circuitry comprising theprocessor 20 may be configured to control one or more functions of oneor more elements of the user interface through computer programinstructions, for example, software and/or firmware, stored on a memoryaccessible to the processor 20, for example, volatile memory 40,non-volatile memory 42, and/or the like. The apparatus 10 may include abattery for powering various circuits related to the mobile terminal,for example, a circuit to provide mechanical vibration as a detectableoutput. The user input interface may comprise devices allowing theapparatus 20 to receive data, such as a keypad 30 (which can be avirtual keyboard presented on display 28 or an externally coupledkeyboard) and/or other input devices.

As shown in FIG. 8, apparatus 10 may also include one or more mechanismsfor sharing and/or obtaining data. For example, the apparatus 10 mayinclude a short-range radio frequency (RF) transceiver and/orinterrogator 64, so data may be shared with and/or obtained fromelectronic devices in accordance with RF techniques. The apparatus 10may include other short-range transceivers, such as an infrared (IR)transceiver 66, a Bluetooth™ (BT) transceiver 68 operating usingBluetooth™ wireless technology, a wireless universal serial bus (USB)transceiver 70, a Bluetooth™ Low Energy transceiver, a ZigBeetransceiver, an ANT transceiver, a cellular device-to-devicetransceiver, a wireless local area link transceiver, and/or any othershort-range radio technology. Apparatus 10 and, in particular, theshort-range transceiver may be capable of transmitting data to and/orreceiving data from electronic devices within the proximity of theapparatus, such as within 10 meters, for example. The apparatus 10including the Wi-Fi or wireless local area networking modem may also becapable of transmitting and/or receiving data from electronic devicesaccording to various wireless networking techniques, including 6LoWpan,Wi-Fi, Wi-Fi low power, WLAN techniques such as IEEE 802.11 techniques,IEEE 802.15 techniques, IEEE 802.16 techniques, and/or the like.

The apparatus 10 may comprise memory, such as a subscriber identitymodule (SIM) 38, a removable user identity module (R-UIM), a eUICC, anUICC, and/or the like, which may store information elements related to amobile subscriber. In addition to the SIM, the apparatus 10 may includeother removable and/or fixed memory. The apparatus 10 may includevolatile memory 40 and/or non-volatile memory 42. For example, volatilememory 40 may include Random Access Memory (RAM) including dynamicand/or static RAM, on-chip or off-chip cache memory, and/or the like.Non-volatile memory 42, which may be embedded and/or removable, mayinclude, for example, read-only memory, flash memory, magnetic storagedevices, for example, hard disks, floppy disk drives, magnetic tape,optical disc drives and/or media, non-volatile random access memory(NVRAM), and/or the like. Like volatile memory 40, non-volatile memory42 may include a cache area for temporary storage of data. At least partof the volatile and/or non-volatile memory may be embedded in processor20. The memories may store one or more software programs, instructions,pieces of information, data, and/or the like which may be used by theapparatus for performing operations, such as process 400 and/or anyother operations/functions disclosed herein. The memories may comprisean identifier, such as an international mobile equipment identification(IMEI) code, capable of uniquely identifying apparatus 10. The memoriesmay comprise an identifier, such as an international mobile equipmentidentification (IMEI) code, capable of uniquely identifying apparatus10. In the example embodiment, the processor 20 may be configured usingcomputer code stored at memory 40 and/or 42 to control and/or provideone or more aspects disclosed herein with respect to process 400including for example advertising degree of interference, the first timeperiod of a first CCA range, and/or the second time period of a secondCCA range, receiving neighboring node interference degrees, determiningdifferences in interference degrees, and/or adjusting CCA range,receiver sensitivity, and/or transmit power based on the interferencedegrees (for example, the difference between an access point'sinterference degree and the interference degrees of its neighboringnodes).

Some of the embodiments disclosed herein may be implemented in software,hardware, application logic, or a combination of software, hardware, andapplication logic. The software, application logic, and/or hardware mayreside on memory 40, the control apparatus 20, or electronic components,for example. In some example embodiment, the application logic, softwareor an instruction set is maintained on any one of various conventionalcomputer-readable media. In the context of this document, a“computer-readable medium” may be any non-transitory media that cancontain, store, communicate, propagate or transport the instructions foruse by or in connection with an instruction execution system, apparatus,or device, such as a computer or data processor circuitry, with examplesdepicted at FIG. 8, computer-readable medium may comprise anon-transitory computer-readable storage medium that may be any mediathat can contain or store the instructions for use by or in connectionwith an instruction execution system, apparatus, or device, such as acomputer.

Without in any way limiting the scope, interpretation, or application ofthe claims appearing below, a technical effect of one or more of theexample embodiments disclosed herein may be improved frequency re-useand/or fairness for high density deployments.

The subject matter described herein may be embodied in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. For example, the base stations and user equipment (or oneor more components therein) and/or the processes described herein can beimplemented using one or more of the following: a processor executingprogram code, an application-specific integrated circuit (ASIC), adigital signal processor (DSP), an embedded processor, a fieldprogrammable gate array (FPGA), and/or combinations thereof. Thesevarious implementations may include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device. Thesecomputer programs (also known as programs, software, softwareapplications, applications, components, program code, or code) includemachine instructions for a programmable processor, and may beimplemented in a high-level procedural and/or object-orientedprogramming language, and/or in assembly/machine language. As usedherein, the term “computer-readable medium” refers to any computerprogram product, machine-readable medium, computer-readable storagemedium, apparatus and/or device (for example, magnetic discs, opticaldisks, memory, Programmable Logic Devices (PLDs)) used to providemachine instructions and/or data to a programmable processor, includinga machine-readable medium that receives machine instructions. Similarly,systems are also described herein that may include a processor and amemory coupled to the processor. The memory may include one or moreprograms that cause the processor to perform one or more of theoperations described herein.

Although a few variations have been described in detail above, othermodifications or additions are possible. In particular, further featuresand/or variations may be provided in addition to those set forth herein.Moreover, the implementations described above may be directed to variouscombinations and subcombinations of the disclosed features and/orcombinations and subcombinations of several further features disclosedabove. Other embodiments may be within the scope of the followingclaims.

If desired, the different functions discussed herein may be performed ina different order and/or concurrently with each other. Furthermore, ifdesired, one or more of the above-described functions may be optional ormay be combined. Although various aspects of some of the embodiments areset out in the independent claims, other aspects of some of theembodiments comprise other combinations of features from the describedembodiments and/or the dependent claims with the features of theindependent claims, and not solely the combinations explicitly set outin the claims. It is also noted herein that while the above describesexample embodiments, these descriptions should not be viewed in alimiting sense. Rather, there are several variations and modificationsthat may be made without departing from the scope of some of theembodiments as defined in the appended claims. Other embodiments may bewithin the scope of the following claims. The term “based on” includes“based on at least.” The use of the phase “such as” means “such as forexample” unless otherwise indicated.

What is claimed:
 1. A method comprising: determining, at a node, adegree of interference at the node; receiving, at the node, at least onemessage from at least one neighboring node, the at least one messageincluding another degree of interference observed at a first neighboringnode of the at least one neighboring node; determining, at the node, adifference between the degree of interference at the node and thereceived another degree of interference; and adjusting, by the node andbased on the difference, at least one of a receiver sensitivity of thenode and a clear channel assessment detection range of the node.
 2. Themethod of claim 1, wherein the adjusting further comprises: adjusting,based on the difference, a transmit power of the node.
 3. The method ofclaim 1, wherein the receiving comprises listening to at least onebeacon transmitted by the at least one neighboring node.
 4. The methodof claim 1, further comprising: determining an aggregate for the anotherdegree of interference and one or more additional degrees ofinterference; and adjusting, based on the aggregate, at least one of thereceiver sensitivity of the node, the clear channel assessment detectionrange of the node, and a transmit power of the node, wherein the one ormore additional degrees of interference are observed at one or moreneighboring nodes of the at least one neighboring node other than thefirst neighboring node.
 5. The method of claim 4, wherein determiningthe aggregate comprises determining at least one of a median, a mode, asecond order statistic, or a weighted average.
 6. The method of claim 1further comprising: adjusting, for a first time period, the clearchannel assessment detection range of the node to a first range; andadjusting, for a second time period, the clear channel assessmentdetection range of the node to a second range that is different from thefirst range.
 7. The method of claim 1, wherein the adjusting comprisesincreasing the clear channel assessment detection range of the node toincrease the degree of interference at the node.
 8. The method of claim1, wherein the adjusting comprises decreasing the clear channelassessment detection range of the node to decrease the degree ofinterference at the node.
 9. The method of claim 1, wherein the nodecomprises an access point.
 10. An apparatus comprising: at least oneprocessor; and at least one memory including computer program code, theat least one memory and the computer program code configured to, withthe at least one processor, cause the apparatus to at least: determine,at the apparatus, a degree of interference at the apparatus; receive, atthe apparatus, at least one message from at least one neighboring node,the at least one message including another degree of interferenceobserved at a first neighboring node of the at least one neighboringnode; determine, at the apparatus, a difference between the degree ofinterference at the apparatus and the received another degree ofinterference; and adjust, by the apparatus and based on the difference,at least one of a receiver sensitivity of the apparatus and a clearchannel assessment detection range of the apparatus.
 11. The apparatusof claim 10, wherein the apparatus is further configured to at least:adjust, based on the difference, a transmit power of the apparatus. 12.The apparatus of claim 10, wherein the apparatus is further configuredto at least: listen to at least one beacon transmitted by the at leastone neighboring node.
 13. The apparatus of claim 10, wherein theapparatus is further configured to at least: determine an aggregate forthe at least another degree of interference and one or more additionaldegrees of interference; and adjust, based on the aggregate, at leastone of the receiver sensitivity of the apparatus, the clear channelassessment detection range of the apparatus, and a transmit power of theapparatus, wherein the one or more additional degrees of interferenceare observed at one or more neighboring nodes of the at least oneneighboring node other than the first neighboring node.
 14. Theapparatus of claim 13, wherein the apparatus is further configured to atleast: determine at least one of a median, a mode, a second orderstatistic, or a weighted average.
 15. The apparatus of claim 10, whereinthe apparatus is further configured to at least: adjust, for a firsttime period, the clear channel assessment detection range of theapparatus to a first range; and adjust, for a second time period, theclear channel assessment detection range of the apparatus to a secondrange that is different from the first range.
 16. The apparatus of claim10, wherein the apparatus is further configured to at least adjust by atleast increase the clear channel assessment detection range of theapparatus to increase the degree of interference at the apparatus. 17.The apparatus of claim 10, wherein the apparatus is further configuredto at least adjust by at least decrease the clear channel assessmentdetection range of the apparatus to decrease the degree of interferenceat the apparatus.
 18. The apparatus of claim 10, wherein the apparatuscomprises an access point.
 19. A non-transitory computer-readablestorage medium including computer program code which when executed by atleast one processor cause operations comprising: determining, at a node,a degree of interference at the node; receiving, at the node, at leastone message from at least one neighboring node, the at least one messageincluding another degree of interference observed at a first neighboringnode of the at least one neighboring node; determining, at the node, adifference between the degree of interference at the node and thereceived another degree of interference; and adjusting, by the node andbased on the difference, at least one of a receiver sensitivity of thenode and a clear channel assessment detection range of the node.